title: Efficient boosting of the antiviral T cell response in B cell-depleted patients with autoimmune rheumatic diseases following influenza vaccination.
abstract: OBJECTIVE
  Booster vaccination against 2009 H1N1 influenza virus was recommended for rheumatologic patients under immunosuppressive therapy during the 2009/2010 H1N1 pandemic. In this study we assessed whether B cell depletion with rituximab influences of the antiviral immune response in 2009 H1N1 influenza virus-vaccinated patients.
  
  
  METHODS
  Influenza virus-specific immune responses were analysed after the first and a booster vaccination with pandemrixTM in sixteen consecutive rituximab-treated patients with different rheumatic autoimmune disorders. Antibody titers were determined by a haemagglutination-inhibition assay and virus-specific T cell responses were evaluated by a flow cytometry-based intracellular cytokine-secretion assay. Patients showing clinical symptoms of influenza infection were excluded from this study.
  
  
  RESULTS
  Two out of seven patients with low (<10%) and four out of nine with normal (>10%) B cells developed significant antibody responses after the first vaccination. Booster vaccination led to an antibody response in one additional patient. After the first vaccination, virus-specific CD4+ and CD8+ T cell responses were significantly lower in patients with low B cells than in those with normal B cells. Of importance, the booster vaccination stimulated the antiviral T cell response only in patients with low B cells.
  
  
  CONCLUSIONS
  In the absence of a significant effect of booster vaccinations against 2009 H1N1 influenza virus on the humoral immune response in B cell-depleted patients with autoimmune rheumatic diseases, enhanced antiviral T cell responses in patients with low B cells indicate that T cells, maybe, compensate for the impaired humoral immunity in these patients.
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, Kantonsspital St. Gallen, St. Gallen, Switzerland. ruediger.mueller@kssg.ch.
authors.forename: Rudiger B
authors.initials: RB
authors.lastname: Muller
authors.forename: Reinhard
authors.initials: R
authors.lastname: Maier
authors.forename: Katja
authors.initials: K
authors.lastname: Hoschler
authors.forename: Maria
authors.initials: M
authors.lastname: Zambon
authors.forename: Burkhard
authors.initials: B
authors.lastname: Ludewig
authors.forename: Martin
authors.initials: M
authors.lastname: Herrmann
authors.forename: Hendrik
authors.initials: H
authors.lastname: Schulze-Koops
authors.forename: Johannes
authors.initials: J
authors.lastname: von Kempis
mesh_terms: D000328:Adult; D000368:Aged; D058846:Antibodies, Monoclonal, Murine-Derived / Q000009:adverse effects / Q000627:therapeutic use*; D000914:Antibodies, Viral / Q000097:blood; D001327:Autoimmune Diseases / Q000097:blood / Q000188:drug therapy* / Q000276:immunology; D001402:B-Lymphocytes / Q000187:drug effects* / Q000276:immunology / Q000821:virology; D015415:Biomarkers / Q000097:blood; D016009:Chi-Square Distribution; D005260:Female; D006801:Humans; D056724:Immunity, Humoral / Q000187:drug effects; D007117:Immunization, Secondary; D007166:Immunosuppressive Agents / Q000009:adverse effects / Q000627:therapeutic use*; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology*; D007252:Influenza Vaccines / Q000276:immunology*; D007251:Influenza, Human / Q000276:immunology / Q000517:prevention & control* / Q000821:virology; D008212:Lymphocyte Depletion; D008297:Male; D008875:Middle Aged; D012216:Rheumatic Diseases / Q000097:blood / Q000188:drug therapy* / Q000276:immunology; D000069283:Rituximab; D013601:T-Lymphocytes / Q000187:drug effects* / Q000276:immunology / Q000821:virology; D013997:Time Factors; D055815:Young Adult
chemical_list: D058846:Antibodies, Monoclonal, Murine-Derived; D000914:Antibodies, Viral; D015415:Biomarkers; D007166:Immunosuppressive Agents; D007252:Influenza Vaccines; C556153:pandemrix; D000069283:Rituximab